Engine apparatus

ABSTRACT

Improved system for supplying fuel and oil to two-cycle internal combustion engines including a simple and reliable fuel-oil injector pump which mixes the fluids in a desired ratio from separate tanks. Means for automatically shutting off fuel flow upon loss of oil are provided. Crankcase scavenging pressure assists oil pumping. The injector pump continuously circulates fuel through the fuel tank to avoid vapor lock. Several arrangements for properly correlating the injector pumping rate with engine air flow are disclosed. An improved injection nozzle utilizing an elastomeric band is disclosed. A system for supplying dual cylinders from the same injector pump is disclosed.

United States Patent 1191 Ulbing 1 Jan. 2, 1973 54] ENGINE APPARATUS3,212,485 l0/l965 Werner-ct al ..123/73 AD In entor: otmar M. Lise,Leitermann el al Assisnee Borg-Warner Corporation, Chicago, PrimaryExaminer-Wendell E. Burns Altorney-Richard G. Stephens [22] Filed: June1, 1971 [57] ABSTRACT [211 App]. No.: 148,867

improved system for supplying fuel and oil to two- Related ApplicationData cycle internal combustion engines including a simple [63]Continuation ofser No 6233mm, 1968 and reliable fuel-oil injector pumpwhich mixes the fluids in a desired ratio from separate tanks. Means for52 5, 3 123 73 23 9 R, 17 17 automatically shutting off fuel flow uponloss of oil are [51] Int. Cl ..F02h 33/04 prcvidedcrankcase vengingpressure assist oil [58] Field of Search ..l23/73 AD, 119 R;417/3l7pumping. The injector pump continuously circulates fuel through the fueltank to avoid vapor lock. Several [56] References Cited arrangements forproperly correlating the injector pumping rate with engine air flow aredisclosed. An UNITED STATES PATENTS improved injection nozzle utilizingan elastomeric 2,935,057 5/1960 Perlewitz ..123/73 AD band is disclosed.A system for supplying dual cylin- 3,l40,700 7/1964 Nallinger ...l23/73AD ders from the same injector pump is disclosed. 3,114,356 12/1963Werner et al. ....l23/73 AD 3,202,102 8/1965 Staege et al 123/73 AD 16Claims, 18 Drawing Figures SHEET U30F 1O PATENTEBJAN 2191s PATENTEDJAN2197s SHEET USUF1O PATENTEUJAN 2197a SHEET GBUF 1O PATENTEDM 2191s I3.707.955 SHEET U7UF 10 FlG.3e

PATENTEDJAN 2197s SHEET U8UF 1O PATENTEDJM 2873 1 3,707,955

sum 09m 10 4 ENGINE APPARATUS This application is a continuation of myprior application Ser. No. 786,233 filed Dec. 23, 1968. This inventionrelates to two-cycle gasoline engines, to fuel and lubrication injectionand control systems for the same, and various features of the inventionhave application to other types of engines and even various nonengineapplications.

A wide variety of machines, such as snowmobiles, motorcycles and variousother devices utilize two-cycle gasoline engines, ordinarily because ofthe lower cost per horsepower and lesser weight per horsepower of suchengines, and their lower cost is the primary reason why two-cycleengines are preferred to four-cycle engines in many such applications.Despite their mentioned advantages, twocycle engines have not met withfavor in a number of applications due to the necessity of providing agasoline-oil mixture in order to ensure lubrication of the enginecrankcase bearings and the cylinder walls. Providing a mixture ofgasoline and oil in the proper ratio is troublesome and time-consuming,and many two-cycle engines have been ruined because the ratio of themixture has been wrong. While the calculation of proper amounts of oiland proper amounts of fuel to provide a desired ratio involves onlyelementary mathematics and a modicum of care, experience has shown thatin the ordinary applications of many two-cycle engines the mistakes ofunskilled or careless persons result in improper ratios frequently beingused, often to the detriment of the engine. It is one object of thepresent invention to provide a two-cycle engine system in which oil andgasoline may be supplied to two respective tanks with no pre-rnixingbeing required and in which means are provided to automatically mix theoil and gasoline in the proper ratio as they are used, so that nopre-mixing is required, and so that the proper mixture or ratio isalways provided, no matter whether the engine is running fast or slow.in some applications different mixture ratios are desirable at differentengine speed and load conditions, and it is another object of theinvention to provide a system in which mixture ratio may be arranged tovary automatically with the flow rate of the fuel-oil mixture suppliedto the engine.

Cost is a major factor in many of the applications for which two-cycleengines are utilized, and most, if not all, prior two-cycle engines haveutilized carburetors rather than fuel injection systems, due to the highcost and complexity of prior fuel injection systems. However,carburetors have a number of disadvantages which are overcome by thepresent invention. For example, carburetors are difficult to adjust,even by skilled mechanics sometimes, and they frequently requirere-adjustment. [t is another object of the present invention to providea fuel-oil injection system for two-cycle engines which requires nocomplex adjustment procedure and which does not require periodicreadjustment. Carburetors also become clogged frequently, due to thesmall passages necessarily included in them and the low pressures whichthey develop, and one object of the present invention is to provide afuel-oil injection system for a two-cycle-engine which is lesssusceptible to clogging. Carburetion systems frequently are plagued byvapor lock problems, 6

and a further object of the invention is to provide a fuel-oil injectionsystem which overcomes vapor lock problems, which otherwise often occurin two-cycle engine systems during high heat conditions. Another objectof the invention is to provide an improved fuel-oil injection systemwhich insures better starting of a twocycle engine in cold weather whenoil viscosity may be rather high.

While a number of two-cycle engine systems utilizing carburetion havebeen deemed satisfactory for constant load or other specificload-applications, they have been disadvantageous in not beingcontrollable over a very wide range of speeds. It is a further object ofthe invention to provide a two-cycle engine system which can runsmoothly, under varying load conditions, over a greater range of speeds.The present invention also allows a two-cycle engine to provide higherpower output at a given speed, both at low and high speeds, and allowsthe engine to accelerate and decelerate without the delay whichaccompanies some carburetion systems.

In ordinary two-cycle engine systems involving carburetion, little or nofuel-oil mixture is supplied to the engine intake manifold, and hencelittle or no engine lubrication is provided, unless the carburetorthrottle plate is open, i.e., unless the accelerator pedal is depressed,for example, in a snowmobile, even though the snowmobile may betraveling at a high speed and the engine turning at a high speed, withthe result that many two-cycle engines have been ruined for lack oflubrication when a snowmobile, for example, coasts down a long, steephill with the engine running slowly and braking the snowmobile. Mosttwo-cycle engines can operate in such an overrunning condition for onlyperhaps 60 or 90 seconds without seriously damaging the engine. It isanother important object of the invention to provide a two-cycle enginesystem wherein such operation is automatically prevented.

If a two-cycle engine is operated for any substantial length of timewithout lubrication, it rapidly will be damaged, as just mentioned. Ifpre-mixing of gasoline and oil is to be avoided and gasoline and oil areinstalled in separate tanks without the need for measuring preciseamounts of each, and if the gasoline and oil are automatically dispensedfrom the two tanks with the proper ratio, it will be apparent that onetank well may become emptied before the other, and that if the oilsupply became depleted before the gasoline supply, continued running ofthe engine might seriously damage the engine. Thus it is anotherimportant object of the invention to provide a two-cycle fuel-oilinjection system in which the engine will be automatically shut off ifthe oil supply fails while the engine is running, so that damage to theengine will not result.

' The invention also includes a novel, inexpensive and reliableinjection nozzle assembly which efficiently atomizes the mixturesupplied by the injector of the invention. Attending each of theaforementioned objects is the very important object of providing a fuelinjection system for a two-cycle engine which is inexpensive, compact,and reliable, having no delicate parts which are subject to failure ormisadjustment. Further objects of the invention are to provide a fuelinjection pump wherein lesser pressures are built up across the pumppiston for a given pumping flow rate so that less precisepiston-cylinder tolerance is required, and a pump in which delivery perstroke is substantially independent of pump speed, supply pressure, andcheck valve load- Two-cylinder two-cycle engines often utilize twocarburetors rather than a single carburetor in order to provide greaterpower output. If one carburetor fails such engines frequently continueto run on one cylinder, and the lack of lubrication then experienced bythe cylinder fed by the failed carburetor may cause considerable damage.It is another object of the invention to provide a fuel-oil injectionsystem for a two-cylinder two-cycle engine which prevents thepossibility of such damage.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts, which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a side view of a two-cycle engine showing portions of a systemconstructed in accordance with the present invention.

FIG. 2 is a cross-section view of one form of fuel-oil injector pumpconstructed in accordance with the present invention, with additionalparts of a fuel and oil control system shown schematically.

FIG. 2a is a view taken at lines 2-2 in FIG. 2.

FIG. 2b is a view taken at lines 3-3 in FIG. 2 with plug 64b removed.

FIG. 2c is a diagrammatic view useful in illustrating the operation ofthe pump of FIGS. 2, 2a and 2b.

FIG. 3 is a cross-section view taken at lines 4-4 in FIG. 3b through afurther form of fuel-oil injection pump. 1

FIG. 3a is a view taken at lines 5-5 in FIG. 3 with piston 161 andsprings 133 and 162 removed.

FIG. 3b is a view taken at lines 6-6 in FIG. 3a.

FIG. 3c is a view taken at lines 7-7 in FIG. 3.

FIG. 3d is a view taken at lines 8-8 in FIG. 3.

FIG. 3e shows a portion of an injector pump of the type shown in FIGS 3and 3a-3d connected to be controlled by control apparatus illustratedschematically.

FIG. 4 is a side view of the engine showing one manner in which theinjector pump of the present invention may be arranged to be operatedfrom the crankshaft (or other shaft) of an engine.

' FIG. 5a is a front view of the air intake duct of the engine system ofFIG. 1.

FIG. 5b is a side view of the air intake duct of the engine system ofFIG. 1.

FIG. 6 is a side view of a portion of the system of FIG. 1 illustratingthe atomizing injector nozzle of the present invention.

FIG. 6a is an enlarged isometric view of a part of the nozzle assemblyof FIG. 6.

FIG. 6b is a view taken at lines 9-9 in FIG. 6.

FIG. 7 is a view partially cutaway illustrating use of an injector pumpto supply both cylinders of a dual cylinder two-cycle engine.

Referring now to FIG. 1, a known type of two-cycle engine 10 is shown asincluding an externally-finned cylinder 11 having a single piston(notshown) inside, spark plug 13 and crankcase 14. FIG. 1 is drawn toresemble the basic structure of a Series SA 290 Model 297-68 engine,(Ser. No. 5529 098) manufactured by Sachs GmbI-I in Germany andcommercially available in the United States. Engine 10 is provided withan air intake duct or chamber 15 which communicates directly with theinput duct (not shown in FIG. 1) 5 through which fuel (and oil) areadmitted to the crankcase of engine 10. Intake chamber 15 (or manifoldin the case of multicylinder engines) includes an open end to admit airand includes an adjustable throttle plate (not shown in FIG. 1), theadjustment of which controls the air flow through passage 15. Thethrottle plate corresponds in one basic principle to the throttle plateused to choke ordinary carbureted engines. A fuel-oil mixture injectionnozzle assembly 18 includes a nozzle which extends into intake chamber15. A fuel-oil mixture is supplied to the nozzle of assembly 18 viatubing 18a from injector pump 12. Various preferred details of thenozzle 18 assembly will be further explained in connection with FIG. 6.Engine 10 is a common type of two-cycle engine of thecrankcase-scavenged type, having a hermetically-sealed crankcase inwhich the pressure changes as the piston rises and descends. It willbecome apparent as the description proceeds that the invention isapplicable as well to two-cycle engines of the type which use a separatescavenging fan or pump.- Furthermore, while engine 10 is shown as a typewherein gasoline and oil are applied as a mixture to an intake chamber,it will become apparent that many aspects of the invention areapplicable as well to twocycle engines of the autolube type wherein oilis not mixed with the gasoline prior to its introduction-into theengine, but instead pumped through suitable conduits to specific bearingor other desired lubrication points within the engine.

FIGS. 2, 2a and 2b illustrate one form of injector pump constructed inaccordance with the present invention, and FIG. 2c is a porting diagramuseful in illustrating the operation of that fuel injector, whichutilizes a number of the principles of the pump illustrated in my priorUS. Pat. No. 2,969,738. The fuel injector comprises a central casting orhousing 20 preferably of aluminum, having a rear head 21 and a fronthead 22 bolted thereto, with suitable gaskets 21a and 21b therebetween.Four mounting holes 20f, 20f (FIG. 2) are provided through casting 20 tomount the injector pump on the engine crankcase. Three mounting holes20g, 20g (FIG. 2b) are provided to bolt each head to central casting 20.Shaft 23 driven by the engine crankshaft through pulley 24 and a timingbelt 25 (FIG. I) is journalled in casting 20 and extends through oilseal 26 (FIG. 2a). in one wall of housing 20 and carries eccentric cam27 which is disposed within hollow chamber 28. A domed circular cup 23a(FIG. 2a) press-titted into one side of casting 20 closes the side ofthe casting and axially locates shaft 23. Casting 20 also includes alongitudinally-extending bore 29 which extends into chamber 28.Generally cylindrical sleeve 20a is press-fitted into placein bore 29,and piston 30 is situated within sleeve 290, which is provided with aplurality'of ports, as will be described. Control rod 31 is rotatablyjournalled in rear head 21 and secured against axial movement by meansof snap rings 32a, 32b which engage circumferential slots in rod 31. U-shaped return spring means 33 interconnects piston 30v and control rod31, the forked ends of spring 33 engaging pins 34 and 35 which extendthrough respective ends of rod 31 and piston 30. As the enginecrankshaft rotates pulley 24 and shaft 23, eccentric cam 27 will be seento urge piston rightwardly against the force of spring means 33 during aportion of each revolution of cam 27, and the spring means will returnpiston 30 leftwardly during another portion of each revolution, andhence piston 30 will reciprocate back and forth a predetermined distancewithin bore 29 during each cam revolution. Inasmuch as control rod 31 isrotatably journalled in head 21 and piston 30 is rotatable within bore29, angular rotation of control rod 31 will be seen to act throughspring means 33 to similarly angularly rotate piston 30.

Cylindrical sleeve 29a has a plurality of ports 34-37 and piston 30 isprovided with a plurality of external grooves 38, 39 which extendpartially around the periphery of piston 30, and hence angular rotationof piston 30 about longitudinal axis x-x by means of control rod 31serves to angularly position grooves 38, 39 with respect to ports 34-37.Ports 34-37 are each shown as comprising a slot which extends partiallyaround sleeve 29a, with each slot having a uniform width measured in theaxial direction of sleeve 29a. Oil intake port 34 in sleeve 29a connectsto hollow chamber 28 through passage 41, an axially-extending slotmilled in sleeve 29a. Oil outlet port connects through passage 42a tocheck valve 50 situated within passage 4212, which extends to mixingchamber 43 provided within front head 22. A ball 42c plugs the end ofpassage 42a. Fuel (gasoline) intake port 36 connects via passage 44, alongitudinally-extending slot milled in sleeve 29a, to fuel inletchamber 64 and thence via fuel supply lines 45a, 45b to fuel tank 46,and fuel outlet port 37 connects via passages 47a, 45b and check valve51 to mixing chamber 43.

Each of the grooves 38, 39 on piston 30 comprises a V-shaped groovemilled on the periphery of cylindrical piston 30, with the depth of eachV-groove equal to approximately half the diameter of piston 30, so thatthe apices of each V-groove are spaced apart approximately 180 from eachother around piston 30. Piston 30 is shown rotated 90 from its ordinaryoperating range of positions in order to afford a better view ofV-grooves 38 and 39. Ports 34-37 in sleeve 29a are each shown extendingperpendicularly to axis x-x. The relationship of V-groove 38 to oilintake and outlet ports 34 and 35, and the similar relationship ofV-groove 39 to fuel intake and outlet ports 36 and 37, are betterillustrated by the geometric diagram of FIG. 2c wherein the outsidesurface of piston 30 and the inside surface of sleeve 29a are showndeveloped, or unrolled, and superimposed on each other. The use of aV-shaped milling tool having straight sides will be recognized toprovide grooves on cylindrical sleeve 29a of the nature shown at 38 and39 in FIG. 20. 1

FIG. 20 illustrates in solid lines a condition where piston 30 is at itsleftward limit of travel and where piston 30 has been rotated by controlrod 31 to an angular position to provide a minimum or a very low pumpingrate. V-groove 38 will be seen to communicate with or substantiallyregister with oil intake port 34, and V-groove 39 to substantiallyregister with fuel intake port 36, while oil outlet port 35 and fueloutlet port 37 will be seen to be blocked. Rightward travel of piston 30in FIG. 2 is represented by rightward movement of V-grooves 38 and 39relative to ports 34-37 in FIG. 2c. As piston 30 moves rightwardly inFIG. 2c, V- groove 38 will be seen to register less and less with port34, and nearer and nearer toward a position where it will register withport 35. The shape of groove 38 and the locations of ports 34 and 35 areestablished so that groove 38, over its entire stroke, will communicatewith at least one or the other ports 34, 35, and at all angularpositions of piston 30, groove 38 will communicate with both ports 34and 35 during a certain portion of each stroke.

With piston 30 in the angular position shown in solid lines in FIG. 2c,it will be seen that groove 38 will register with port 34 during most ofthe piston stroke (the total length of which is indicated by distancesin FIG. 20) and will register with port 35 only during a very smallterminal portion of the rightward stroke. If piston 30 is rotated withinbore 29, however, such as to a medium position indicated by groove 38 indashed lines at 380 in FIG. 20, it will be seen that groove 38 will becutoff from inlet port 34 earlier during the rightward stroke and willregister with outlet port 35 during a substantial portion of the stroke.If piston 30 is further rotated within bore 29, so that groove 38 can berepresented at 38b in FIG. 2c, it will be. seen that groove 38 willcutoff from inlet port 34 and communicate with outlet port 35 very earlyduring the rightward stroke. Thus by angularly positioning piston 30within bore 29 by means of control rod 31, one may control the relativetimes during a stroke during which the two ports 34 and 35 communicatewith movable piston groove 38. Groove 39 operates relative to ports 36and 37 in precisely the same way that groove 38 operates relative toports 34 and 35. Inasmuch as grooves 38 and 39 are fixedly spacedrelative to each other on piston 30, and inasmuch as ports 34-37 are allfixedly spaced relative to each other in bore 29, it will be seen thatthe opening and closing of inlet and outlet ports are permanentlysynchronized with each other, need no adjustment and cannot get out ofadjustment.

Referring back now to FIG. 2, it will be seen that piston 30 includes acentral longitudinal bore 55 and a hollowed-out right end portion 56which communicates with the portion of bore 29 on the righthand side ofpiston 30, to provide chamber 60. Oil piston 61 fits within bore 55 andinner coil spring 62 urges oil piston 61 rightwardly from piston 30.Chamber 60 is shown as including a valve seat 63 against which end 61aof piston 61 is seated by the force of spring 62 to close off chamber 60from chamber 64. In many embodiments of the invention valve 610-63 maybe omitted, and piston 61 may, if desired, be rigidly affixed to theright end of chamber 60, and then inner coil spring 62 is not required.Even if no valve or passage is provided at 64, I prefer however, not torigidly affix, the right end of piston 61, and to allow spring 62 tourge piston 61 rightwardly against the closed right end of chamber 60,as allowing piston 61 to float rather than permanently affixing it tochamber 60 obviates precision alignment problems.

To understand the operation of the fuel injector of FIG. 2, first assumewith piston 30 at its left limit of travel that chamber 28, passage 41,oil intake port 34, V-groove 38 and chamber 65 (the portion of bore 55to the left of piston 61) are all filled with oil. As eccentric cam 27urges piston 30 rightwardly, piston 61 will be seen to expel oil outfrom chamber 65, and since V- groove 38 initially registers only withinlet port 34, oil initially will be pumped back through port 34 intochamber 28. The rightward excursion of piston 30 will be seen to providea suction in chamber 28, thereby accelerating the oil flow from port 34to chamber 28. After further rightward travel of piston 30, groove 33will register with both inlet port 34 and outlet port 35, so that oilthen will be expelled through both ports. And after still furtherrightward travel of piston 30, port 34 will be closed, so that oil willbe expelled only through oil outlet port 35, past check valve 50 tomixing chamber 43. The times during the rightward stroke during whichport 35 is opened and port 34 is closed are determined, it will berecalled, by the angular position of piston 30. I

With fuel supply line 45a connected to fuel inlet port 36, and withV-groove 39 communicating with chamber 60, it will be seen that fuelwill be expelled from chamber 60 back through groove 39 toward the fuelsupply tank 46 during an initial portion of the rightward stroke ofpiston 30, and then expelled through fuel outlet port 37 past checkvalve 51 to mixing chamber 43 during ,a terminal portion of therightward stroke. Because of the fixed relationship shown betweengrooves 38, 39 and ports 34-37, return pumping of oil back through inletport 34 will occur for the same portion of the stroke during which fuelis pumped back into supply line 44, and forward pumping of oil pastcheck valve 50 will occur throughout the same portion of the stroke thatfuel is pumped past check valve 51, and by rotation of piston 30 bycontrol rod 31, the relative amounts of return pumping and forwardpumping which occur on a given stroke can be controlled for both fluids.Inasmuch as oil outlet port 35 and fuel outlet port 37 are opened forthe same portion of each rightward stroke of piston 30, it will be seenthat the relative amounts of the two fluids which are pumped during eachrightward stroke depends solely upon the ratio of the effective areas ofthe two pistons, the effective area A of oil piston 61 being 1111 whered,,, is the diameter of piston 61, and the effective area A, of fuelpiston 30 being 1r(d -d where d is the diameter of piston 30 or bore 29.If A, is arranged to be times A,,, for example, it will be seen that 25times as much fuel as oil will be pumped on a given rightward stroke.With the relative amounts of fuel and oil fixed by the relativeeffective piston areas, it will be seen that a mixture having a desiredfuel-oil ratio always will be obtained, irrespective of the amounts ofeach fluid pumped during a given stroke.

It will be apparent at this point that by proper spacing of the portsand the V-grooves one may provide one extreme angular position of pistonwhich will result in inlet ports 34 and 36 being cutoff and outlet ports35 and 37 being opened very near the beginning of the rightward stroke,thereby to provide maximum pumping, and one may provide another extremeangular position which will result in inlet ports 34 and 36 being cutoffand outlet ports 35 and 37 being opened at or near the end of therightward stroke, so that little or no fluids will be pumped. It isimportant, however, that all angular positions of piston 30 provide atleast some slight overlap between the opening of the outlet ports andthe closure of the inlet ports, in order that blockage of fluid notdamage the injector. While NOS. 2 and 2c illustrate a pump valvingarrangement wherein V- grooves have been provided ,on piston 30, toprovide openings having an edge which varies in longitudinal position asa function of piston angular position, and wherein the cylindricalsleeve has straight slots, each having an edge which does not vary inlongitudinal position as a function of its angular position, it willbecome apparent that equivalent valving may be provided with othercombinations of shapes of grooves and slots. For example, it will beapparent that equivalent operation may be effected through a simplereversal of parts, providing piston grooves of unvarying width andsleeve slots having edges whose longitudinal positions vary with angularposition. Also, it will become apparent upon reflection that it isunnecessary that either a port or its cooperating groove have an edgewhich does not vary longitudinally with angular position, and that bothmay vary, though at different rates, to provide equivalent overalloperation. The specific valving system described in detail is preferred,however, inasmuch as it may be provided accurately and inexpensivelyusing only simple machining operations. Both grooves 38 and 39 may bemilled simultaneously on piston 30 using a pair of spaced V-shapedmilling cutters, and pairs of ports may be milled simultaneously insleeve 290 using straight-sided milling cutters.

In the specific porting system shown both inlet ports open and close atthe same time and both outlet ports open and close at the sametime,irrespective of the angular position of piston 30 in sleeve 29a. Itis possible, however, to vary the relationship between the ports andgrooves so that the time at which the fuel inlet port closes and thetime at which the fuel outlet port opens are not always the same timesat which the oil inlet port closes and the oil outlet port opens, butrather vary relative to each other in accordance with the angularposition of piston 30. For example, if the fuel inlet and outlet portsare given a slight axial cant, as indicated in.

FIG. 20 at 36a and 37a, while oil ports 34 and 35 have no such cant, itwill be'seen that the fuel system will switch from return pumping toforward pumping earlier during each pumping stroke than when the oilsystem switches, with the amount by which fuel forward pumping precedesoil forward pumping varying with the an-.

gular position of piston 30, so that fuel ports of the nature shown at36a and 37a will automatically provide a thinner mixture (i.e., greaterratio of fuel to oil) as the pump flow rate increases. Canting the fuelports in an opposite direction would provide a richer mixture as pumpflow rate increases. Provision of a thinner mixture as flow rateincreases obviously may be provided by giving oil ports 34 and 35 acounterclockwise cant instead of giving fuel ports 36 and 37 theclockwise cant shown at 36a and. 37a, and provision of a clockwise cantat ports 34 and 35 would provide a richer mixture at greater flow rates.It should be apparent at this point that both the oil ports and fuelports may be canted, in either the same or opposite directions, and thatthe relative angular relationship between them will determine the senseand the amount by which the mixture ratio changes as the flow ratevaries, and it will also be apparent that equivalent operationmay beeffected by suitably shaping the piston grooves instead of or inaddition to canting the ports. It is not necessary that canted pairs ofports always utilize straight-sided ports, and if desired canted curvedports may be provided in order that mixture ratio vary with pump flowrate in a desired non-linear manner. Irrespective of whether pump 12provides a fixed maxture at all flow rates or a ratio which varies withpump flow rate, it will be appreciated that the ratio at a given rate isinherently built into the piston-cylinder port geometry and cannot getout of adjustment.

A number of prior art pumps using anguIarly-adjustable pistons forvariable metering of a fluid provide only an inlet port, rather thanboth inlet and outlet ports, so that their pump chambers are in constantcommunication with their outlet check valves, and forward pumping pasttheir check valves occurs as the inlet port is closed off to preventreturn flow. If the fluid supply has positive pressure, it will be seenthat the check valve in such prior systems must be loaded to at leastthe same pressure in order to prevent forward pumping prior to completeclosure of the inlet port. And even if the fluid supply is notpressurized, it should be understood that the pressure in the prior artpump chambers necessarily builds up prior to complete closure of theirinlet ports, in amounts dependent upon the pump speed and the amount ofrestriction to return flow between the pump chamber and the fluidsupply, with the amount of restriction increasing from a basic amount tocomplete blockage as the inlet port is gradually closed off. If forwardpumping is not to occur prior to complete closure of the inlet port, thecheck valve must be loaded to the highest such pressure which may occurprior to inlet port closure. The heavier check valve loading necessarilyresults in higher pressures in the pump chamber, thereby requiring amore precise pistoncylinder fit. In the pump of the present inventionforward-pumping cannot occur prior to opening of an outlet port,irrespective of whether the supply is pressurized, and hence the instantat which forward pumping begins during a pumping stroke remainssubstantially independent of pump speed and outlet check valve loading.

Chamber 28 in FIG. 2 is connected to oil supply tank 75 through a checkvalve 68. As piston 30 starts leftwardly on its return stroke, thepressure in chamber 28 will be seen to increase positively and to tendto continue to increase during further return travel, to a maximum valuedetermined by the setting of check valve 68. Simultaneously, upon thereturn of piston 30, oil outlet check valve 50 prevents reverse flow ofoil from mixing chamber 43, and hence an increasing partial vacuum willbe built up at port 35 and within chamber 65 and V-groove 38. Whenpiston 30 has returned sufficiently far for V-groove 38 to register withinlet port 34, it will be seen that the positive pressure in chamber 28and the partial vacuum in V-groove 38 and chamber 65 will both actcumulatively, to force oil from chamber 28 through port 34 to fillchamber 65 very quickly during the latter portion of the return stroke.

Similarly, fuel inlet port 36 connects to supply tank 46 through checkvalve 74, and as fuel is pumped toward tank 46 during the initialportion of the rightward stroke of piston 30, a positive pressureapproaching the loading of check valve 74 will build up in line 45abetween port 36 and check valve 74. The initial portion of the returnstroke also creates a partial vacuum at Ill port 37 and in chamber 60and V-groove 39, and when V-groove 39 registers with port 36 near theend of the return stroke, the combination of the positive pressure andpartial vacuum result in quick filling of chamber 60. Chambers 65 and 60must be filled very rapidly,

during a small portion of the injector cycle when the engine is runningfast with an appreciable load, and the combination of pressure andvacuum which serves to fill them rapidly is an important feature of theinvention.

Mixing chamber 43 in head 22 connects by means of a threaded connectionat 43a via tubing 18a (FIG. 1) to an injection nozzle in assembly 18which extends into the intake duct 15 of the engine. In applying theinvention to autolube type two-cycle engines, it will be apparent thatthe two passages leading from check valves 50 and 51 should not lead toa mixing chamber, but instead that the fuel passage alone should lead tothe injection nozzle and the oil passage should lead to the lubricationpoints in the engine.

In FIG. 2 an optional modification is illustrated wherein a ball checkvalve 76 is shown interconnecting chamber 65 and chamber 60, and if sucha check yalve is provided, oil outlet port 35, passage 42a and checkvalve 50 may be eliminated. During the rightward piston stroke with suchan arrangement, it will be seen that oil pressure will build up inchamber 65 as soon as oil inlet port 34 is cut off, and the oil willpass through check valve 76 and be mixed with the fuel in chamber 60,and a fuel-oil mixture will be pumped out of chamber 60 during eachstroke.

In FIG. 2 the fuel line from fuel tank 46 is connected to chamber 64with which valve 61a-63 also communicates. It will be seen that thevacuum created in chamber 60 during the return stroke produces adifferential pressure across valve 61a-63 which may be arranged, byselection of the valve 61a area, to overcome spring 62 and urge piston61 leftwardly during each return stroke, so that chamber 60 may befilled from chamber 64 via valve 61a-63 as well as through port 36. Thisadditional means for quickly filling chamber 60 is wholly unnecessary inmost applications of the invention, however. The use of valve 61a-63.does provide a useful safety feature, however. In FIG. 2

the fuel pressure in chamber 60 will be seen to act on piston rod 61tending to move it leftwardly against a combined force applied to piston61 by spring 62 and the oil pressure in chamber 65, and during normaloperation the rightward pressures on piston 61 maintain its valving end61a tightly seated on valve seat 63. If the oil supply in tank shouldrun out, however, the loss of oil pressure in chamber 65 lessens therightward force on piston 61, whereupon the fuel pressure in chamber 60overcomes the force of spring 62, moving valve end 61a off of valve seat63. Fuel in chamber 60 then will be expelled through valve 61a-63 intochamber 64 rather than being pumped out through port 37, and hence theengine will stall. Valve 61a-63 may connect to a conduit which merelyspills the gasoline on the ground, if desired, but preferably it isconnected as shown to return to chamber 64.

In order to insure the transfer of low viscosity oil from tank 75 to theinjector during cold weather, a substantial scavenging pressure (e.g.10-15 psig) from the engine crankcase is supplied via check valve 77 tooil tank 75, which is closed with a pressure-type cap. Oil tank 75connects to oil chamber 28 of the injector through a lightly loadedcheck valve 69 which allows easy flow of oil to chamber 28 during thepumping stroke of injector piston 30, but shunt-connectedoppositely-oriented check valve 68 allows pressure to build up inchamber 28 during a portion of the return stroke. it maybe noted thatthe creation of such .pressure in chamber 28 during the return strokedoes require the use of a stronger return spring at 33.

With positive pressure applied to the oil supply in the mannermentioned, a safety interlock of the same nature as that described inconnection with valve 610-63 may be provided without the use of such avalve. With the oil tank 75 so pressurized, as soon as all the oil isused up air under pressure will be seen to be applied to chambers 28 and65, and the fit of piston 61 in bore 55, even through quite adequate forpumping oil, may be such that the pressurized air will seep past thesides of piston 61 into chamber 60, where the air, which is underpressure, will displace the fuel, which is at atmospheric or a very lowpressure, and shut off the engine, thereby preventing damage when theoil supply becomes entirely depleted.

FIGS. 3 and 3a through 3d illustrate a modified form of injector muchlike that of FIG. 2, but with certain differences which will be pointedout. Parts in FIGS. 3, 3a-3d generally similar to corresponding parts ofFIG. 2 are given similar numbers with 1 prefix, e.g., piston 30 in FIG.2 corresponds to piston 130 in FIG. 3. As best seen in FIGS. 3 and 3d,pulley 124 driven from the crankshaft rotates shaft 123 which carriescam 127. Cam 127 reciprocates tappet 81, which is carried in bushing 82with an O-ring seal 82a. The right end of tappet 81 bears against theleft end of piston 130, which reciprocates within sleeve 129a. A spring133, only a portion of which is shown, is inserted between head 122 anda right-end face of piston 130 and operates to return piston 130. Alower gear sector 83 (FIGS. 3 and 3c) pinned to piston 130 is engaged byupper gear sector 84 pinned to control shaft 131, so that rotation ofshaft 131 angularly positions piston 130. Upper gear sector 84 isaxially wider than lower gear sector 83 so that the gears remainenmeshed as sector 83 reciprocates with piston 130. Oil is supplied tochamber 128 via a pipe connection made at 128a on the side of casting120. Oil and fuel inlet ports are provided in sleeve 129a at 134 and136, and oil and fuel outlet ports are shown at 135 and 137. Oil piston161 is urged rightwardly against head 122 by inner coil spring 162.Holes drilled in main casting 120 at 1420 and 147a connect the outletports with longitudinally-extending passages in which check valves 150and 151 are situated, and plugs 1420, 147c close the ends of passages142 and 1470. Check valves 150 and 151 at the outlet side of theinjector are shown as comprising elastomeric or rubber duckbill valvesof a known type (Part No. VA 3178 of Material VL-422 M2 sold by VernayLaboratories, Yellow Springs, Ohio), and each such valve connects withmixing chamber 143 provided in head 122.

Fuel chamber 164 in the device of FIG.'3 is shown provided with twoconnections 1450 and 145d (FIG. 3b) to the fuel tank 146 through twofurther duckbill check valves 90 and 91 (FIG. 3a) oriented in oppositedirections. If the injector pumping capacity is substantially greaterthan that required to run the engine at full speed under full load, asubstantial amount of fuel will oscillate in and out of fuel chamber 164as piston 130 could be provided, if desired, to similarly connect oilchamber 128 to provide continuous circulation of oil to and from the oiltank.

FIG. 4 shows a modified mounting arrangement in which a portion of theinjector extends within an engine crankcase 114. The mountingarrangement shown in FIG. 4 was developed for use with acommerciallyavailable JLO two-cycle engine Model dTYT-L372L (Ser. No.37220305). Cam 227 carried eccentrically on the engine crankshaft 223 issurrounded by a nonrotatable porous bronze or oilite ring 85,- whichdoes not rotate, but which will be seen to be reciprocated with aplanetary motion as shaft 223 rotates eccentric cam 227. A hemisphericaldepression in ring is engaged by the hemispherical end of tappet 181,which is urged into engagement with ring 85 by the piston return spring(not shown in FIG. 4). Through use of ring 85 it will be seen that muchless sliding motion results between tappet 181 and ring 85 than wouldresult if tappet 181 directly engaged cam 227, and hence much less wearoccurs and any need to periodically adjust the length of tappet 181 orcompensate for a change in the length thereof is obviated. An oil hole86 in the injector opens into the engine crankcase and a passagewayleading therefrom carries oil to lubricate tappet 181. Aside from thedescribed manner in which its tappet is arranged to be reciprocated bythe engine, the injector pump of FIG. 4 otherwise corresponds with thepump of FIG. 3. While cam 227 in FIG. 4 must be circular in order to usering 85, it is important to note that cams 27 and 127 in FIGS. 2 and 3need not be circular, and can include various other shapes to providedesired reciprocating motion of the pistons which they drive.

FIGS. 50 and 5b illustrate the air intake duct and throttle platearrangement of one embodiment of the invention, and FIG. 6 illustratesthe manner in which injection nozzle assembly 18 extends into the engineintake duct. Air intake 15 includes a flange 15a which bolts to theengine adjacent the engine cylinder inlet port. A conventional circularthrottle plate is rotatably mounted on shaft 96 which extends throughduct 15, andshaft 96 is connected by any suitable arrangement tobe-rotated by the vehicle accelerator pedal or throttle control, to openthrottle plate 95 when the engine is to be accelerated. Shaft 97 rigidlyaffixed to duct 15 and extending parallel to throttle-plate shaft 96carries pivot arm 98 and arm 99. Spring 100 affixed to duct urges arm 98clockwise as viewed in FIG. 5b, so that cam follower roller 101 carriedon arm 98 is urged against the periphery of rotatable throttle cam 102.As the accelerator pedal is depressed, throttleplate shaft 96 and cam102 are rotated counterclockwise as viewed in FIG. b, thereby rotatingarm 98 counterclockwise as the throttle plate unblocks that air intakeduct. The lower end of arm 98 connects, by means of an adjustableturnbuckle 103 to crank arm 104, and rightward movement of the lower endof arm 98 rotates the control rod of the fuel injector, rotating piston30 of FIG. 2 (or piston 130 of FIG. 3) so as to increase the amount offuel-oil mixture pumped during each stroke. A wire 105 connected to arm99 leads to an engine choke" control 96, a simple friction-positionedknob. Pulling on control 96 serves to rotate arm 98 counterclockwiseabout shaft 97, withdrawing cam follower roller 101 from cam 102. sothat a large amount of fuel-oil mixture may be supplied to the enginewhile the throttle plate remains almost closed, thereby providing a richmixture desirable for starting a cold engine.

An alternative form of injector control suitable for use in variousindustrial engine applications where rapid acceleration is not asimportant as economy is shown in schematic form in FIG. 3e connected tothe injector of the type shown in FIG. 3, to provide an arrangementwherein the injector is controlled indirectly rather than directly withthe throttle plate opening. The engine crankcase scavenging pressure isapplied via check valve 106 and needle valve or orifice 107 to diaphragm108, and a bleed to atmosphere is provided through needle valve ororifice 108 from the diaphragm chamber. The scavenging pressure in theengine crankcase varies with throttle position and is a fairly accurateindication of the mass flow of air through the engine. The pressureapplied to diaphragm 108 will be seen to be proportional to peakscavenging pressure. The diaphragm is mechanically connected throughcrank arm 204 to rotate the injector control shaft 131 against the forceapplied to crank arm 204 by spring 110, the pressure of the spring beingadjustable by rotating threaded shaft 111 relative to fixed nut 112.Adjustment of spring 110 varies the richness of the air-oil-fuel mixtureapplied to the engine.

The mixing chamber of the injector connects through tubing 18a, which ispreferably very short, to the injector nozzle assembly best seen inFIGS. 6 and 6a. The injector nozzle assembly comprises a tube 215 havinga flared end which seats within an internal ringshaped recess 216provided in the same type of duckbill check valve 218 as thosepreviously mentioned. A generally cylindrical insert 217 preferablyformed of solid hard nylon or the like extends forwardly out through thefront end of the elastomeric duckbill valve for a distance of aboutone-sixteenth inch, and when utilizing a Vernay Laboratories Model VA3178 duckbill valve of the type mentioned, a nylon insert having adiameter of 7/64 inch has proven satisfactory. One insert suitable foruse with that model valve had dimensions shown in FIG. 6a as a through eof 5/32, l/l6, 7/64, /32 and U32 inch, respectively. A portion of theinsert within the valve is tapered down rearwardly to allow the mixtureto completely surround the insert back from the exit end of the valve,and an enlarged tip 217a on the rear end of the insert also engages ringrecess 216 to hold the insert securely within the valve. It will beapparent that the rear end of insert 217 may be held in place byprovision of suitable locking means on the end of tube 215 if desired.The

essential feature of the nozzle assembly is the provision in a flexiblebody having a fluid passageway of a central 5 body having asubstantially circular cross-section, so

that the flexible body grips it on all sides with substantially uniformpressure, over substantially uniform area around the central body. Themixture pumped by the injector completely surrounds insert 217 up towhere the mouth of flexible valve 218 is stretched around thecylindrical insert. Because valve 218 is flexible and stretched aroundan insert which is circular in crosssection, it will be seen that thepressure with which the resilient valve grips the cylindrical insertwill tend to be uniform all the way around the insert, so that flow ofthe fuel-oil mixture will tend to occur evenly all the way around thevalve, thereby providing a thin ring-shaped spray pattern. It will benoted that the spray pattern will remain ring-shaped irrespective of theflow rate out of the nozzle assembly. Experience has shown that theprovision of such a pattern results in very effective atomization of themixture. The front end portion of the cylindrical insert gripped by themouth of the duckbill valve need not be truly cylindrical, but also maytaper (preferably enlarging outwardly). It is highly desirable, however,that that portion of the insert always be circular in cross-section.

The injector nozzle assembly will be seen to be extremely inexpensive,and reliable. Those skilled in the art will readily be recognize that avariety of different elastomeric materials may be utilized to provideinjection nozzles, it being important, of course, that any suchmaterials not be adversely affected by exposure to oil or gasoline. Thediameter of the insert may be varied when different elastomericmaterials are used, of course, to provide a desired tension of the valvemouth around the cylindrical insert, and hence to provide a a desiredpressure drop at the nozzle. While the tension around the ring-shapednozzle mouth ordinarily will need no adjustment, it will be apparentthat an adjustable nozzle may be made of provision of a taper on thenylon insert and provision of adjusting means whereby the insert may bemoved axially relative to the flexible encircling body. It will also beapparent that use of the new nozzle assembly is in no way restricted totwocycle fuel-oil atomization, but may be used in a wide variety ofother applications, with many different fluids. Also, it will beapparent that the various other features of the invention do not requirethe specific nozzle assembly shown and that numerous other types ofnozzles may be utilized.

FIG. 7 illustrates an intake duct or manifold utilized with atwo-cylinder two-cycle engine wherein cylinders C-1 and C-2 operates outof phase, so that only one cylinder is aspirating at a given time. Theinjector nozzle 118 extends downwardly at a slant into the top of aY-shaped duct 315 and points toward apex 315a of the duct. Each arm ofthe Y-shaped duct leads to the input port associated with a respectivecylinder, and the common leg of the duct includes a throttle plate 95asimilar to plate 95 of FIG. 6 which controls air flow. The injector pump(not shown) which feeds nozzle 118 is arranged to operate at twice thespeed of a singlecylinder arrangement by halving the timing pulleydiameter or by providing two eccentric lobes on cam 27, for example.Running out of fuel or oil will be seen to disable both cylinders andstop the two-cylinder engine, obviating the damage which often occurs indual carburetor two-cylinder two-cycle engines-if one car buretorbecomes clogged or otherwise fails.

While I prefer to provide two separate tanks for fuel and oil to avoidrequirement for proper pre-mixing of the two fluids, it will be apparentat this point that simplified versions of the injector pump having asingle V- groove and single inlet and outlet ports and a single outletcheck valve may be provided to pump a premixed mixture of fuel and oilfrom a single tank to an injection nozzle.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained, andsince certain changes may be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. A fuel and oil control system for a two-cycle internal combustionengine having an engine piston connected to a crankshaft and arranged toreciprocate within a ported cylinder supplied by a throttle-controllableair duct, comprising, in combination: a fuel supply tank; an oil supplytank; an injector pump having a cyclically reciprocable pump pistonconnected to be driven in synchronism with said crankshaft, said pumpbeing connected to said fuel supply tank and said oil supply tank andoperable to pump metered amounts of fuel and oil in a predeterminedratio upon reciprocation of said pump piston; first means forsimultaneously controlling the throttling of said air duct and thevolume of fuel and oil pumped by said injector pump; and second meansfor introducing the fuel pumped by said injector pump into said airduct.

2. A system according to claim 1 in which said engine is provided withone or more lubrication points and in which said system includes one ormore passageways arranged to distribute the oil pumped by said injectorpump to said one or more lubrication points.

3. A system according to claim 1 in which said system includes thirdmeans connected to receive and combine said metered amounts of fuel andoil pumped by said injector pump, and in which said second means isconnected to receive a fuel-oil mixture from said third means.

4. A system according to claim 1 in which said first means comprises amechanical linkage connected to the throttle control-of said air ductand operable to adjust said pump. 7

5. A system according to claim 1 in which said first means comprisesmeans responsive to the scavenging pressure in the crankcase of saidengine for adjusting said pump.

6. A system according to claim 1 having valve means for applying thepressure in the crankcase of said engine to pressurize said oil supplytank.

7. A system according to claim 1 in which said injector pump compriasfirst and second piston-cylinder assemblies connected to b reciprocatedin synchronism with each other, said irst piston-cylinder assembly beingconnected to receive fuel from said fuel supply tank and operable todispense said metered amount of fuel, said second piston-cylinderassembly connected to receive oil from said oil supply tank and operableto dispense said metered amount of oil.

8. A system according to claim 1 wherein said injector pump comprisesfirst and second cyclically reciprocating piston-cylinder assemblieseach having an inlet port, an outlet port and a fluid passageway movablebetween successive porting positions wherein the fluid passageway:communicates solely with the inlet port, simultaneously with the inletport and the outlet port, and solely with the outlet port, the inlet andoutlet ports and the movable fluid passageway in both of saidpiston-cylinder assemblies being relatively spaced to reach successiveones of said successive porting positions simultaneously during areciprocation cycle.

' for decreasing the amount of fuel pumped by said injector pump.

11. A system according to claim 7 having valve means responsive to lossof pressure in second pistoncylinder assembly during a portion of thereciprocation cycle of said assemblies for venting said firstpistoncylinder assembly to decrease the amount of fuel pumped by saidfirst piston-cylinder assembly.

12. A system according to claim 7 having a passageway interconnectingthe cylinders of said first and second piston-cylinder assemblies andcheck valve means situated within said passageway.

13. A system according to claim 8 in which said first piston has aneffective area n times as great as the area of said second piston,whereby the metered amount of fuel pumped is n times the metered amountof oil pumped.

14.A system according to claim 8 wherein the piston in each of saidpiston-cylinder assemblies is rotatable relative to its respectivecylinder to vary the times during a reciprocation cycle at which saidsuccessive port ing positions are reached.

15. A system according to claim 8 in which the inlet ports of saidassemblies are respectively connected to said fuel tank and said oilsupply tank through respective check valves, and said pump includes aconduit leading from each of said outlet ports and containing a furthercheck valve.

16. A system according to claim 8 in which one of said piston-cylinderassembliesis mounted within the other of said piston-cylinderassemblies.

s s s s a:

1. A fuel and oil control system for a two-cycle internal combustionengine having an engine piston connected to a crankshaft and arranged toreciprocate within a ported cylInder supplied by a throttle-controllableair duct, comprising, in combination: a fuel supply tank; an oil supplytank; an injector pump having a cyclically reciprocable pump pistonconnected to be driven in synchronism with said crankshaft, said pumpbeing connected to said fuel supply tank and said oil supply tank andoperable to pump metered amounts of fuel and oil in a predeterminedratio upon reciprocation of said pump piston; first means forsimultaneously controlling the throttling of said air duct and thevolume of fuel and oil pumped by said injector pump; and second meansfor introducing the fuel pumped by said injector pump into said airduct.
 2. A system according to claim 1 in which said engine is providedwith one or more lubrication points and in which said system includesone or more passageways arranged to distribute the oil pumped by saidinjector pump to said one or more lubrication points.
 3. A systemaccording to claim 1 in which said system includes third means connectedto receive and combine said metered amounts of fuel and oil pumped bysaid injector pump, and in which said second means is connected toreceive a fuel-oil mixture from said third means.
 4. A system accordingto claim 1 in which said first means comprises a mechanical linkageconnected to the throttle control of said air duct and operable toadjust said pump.
 5. A system according to claim 1 in which said firstmeans comprises means responsive to the scavenging pressure in thecrankcase of said engine for adjusting said pump.
 6. A system accordingto claim 1 having valve means for applying the pressure in the crankcaseof said engine to pressurize said oil supply tank.
 7. A system accordingto claim 1 in which said injector pump comprises first and secondpiston-cylinder assemblies connected to be reciprocated in synchronismwith each other, said first piston-cylinder assembly being connected toreceive fuel from said fuel supply tank and operable to dispense saidmetered amount of fuel, said second piston-cylinder assembly connectedto receive oil from said oil supply tank and operable to dispense saidmetered amount of oil.
 8. A system according to claim 1 wherein saidinjector pump comprises first and second cyclically reciprocatingpiston-cylinder assemblies each having an inlet port, an outlet port anda fluid passageway movable between successive porting positions whereinthe fluid passageway communicates solely with the inlet port,simultaneously with the inlet port and the outlet port, and solely withthe outlet port, the inlet and outlet ports and the movable fluidpassageway in both of said piston-cylinder assemblies being relativelyspaced to reach successive ones of said successive porting positionssimultaneously during a reciprocation cycle.
 9. A system according toclaim 1 in which said pump includes a reciprocating tappet arranged toreciprocate said pump piston, said crankshaft includes a circular cameccentrically-mounted on said crankshaft within the crankcase of saidengine, and a circular porous metal ring surrounds said circular cam andis rotatable relative thereto, said ring having a partly sphericalrecess and said tappet having a partly spherical end adapted to engagesaid recess.
 10. A system according to claim 2 having means operableupon depletion of oil in said oil supply tank for decreasing the amountof fuel pumped by said injector pump.
 11. A system according to claim 7having valve means responsive to loss of pressure in secondpiston-cylinder assembly during a portion of the reciprocation cycle ofsaid assemblies for venting said first piston-cylinder assembly todecrease the amount of fuel pumped by said first piston-cylinderassembly.
 12. A system according to claim 7 having a passagewayinterconnecting the cylinders of said first and second piston-cylinderassemblies and check valve means situated within said passageway.
 13. Asystem according to claim 8 in which said first piston has an effectivearea n times as great aS the area of said second piston, whereby themetered amount of fuel pumped is n times the metered amount of oilpumped.
 14. A system according to claim 8 wherein the piston in each ofsaid piston-cylinder assemblies is rotatable relative to its respectivecylinder to vary the times during a reciprocation cycle at which saidsuccessive porting positions are reached.
 15. A system according toclaim 8 in which the inlet ports of said assemblies are respectivelyconnected to said fuel tank and said oil supply tank through respectivecheck valves, and said pump includes a conduit leading from each of saidoutlet ports and containing a further check valve.
 16. A systemaccording to claim 8 in which one of said piston-cylinder assemblies ismounted within the other of said piston-cylinder assemblies.